Magnetic and superconducting properties of Nd_1.85Ce_0.15CuO₄

Magnetic investigations of the electron-doped superconductor Nd_2-xCe_xCuO₄ (with nominal composition x=0.15) are reported. In a low external field (5 G) the normal state susceptibility obeys the Curie-Weiss law but in higher fields a deviation from this behaviour is observed at T approximately=40 K. From the high-temperature data the value of the Curie temperature theta =-70 K is obtained, indicating antiferromagnetic interactions. Hysteresis measurements give the critical current density of j_c=2.3*10² A cm^-2 in a field of 30 G. From the logarithmic time dependence of the thermoremanent magnetisation we estimate an activation energy of U_o=0.05 eV for thermally induced flux creep.